Telegraph system



H. A. HEISING.

TELEGRAPH SYSTEM.

APPLlcAnoN FILED MA1/12.1915.

Patented May 11,1920.

/nVe/v/o/f.' Raymond /4/7'e/s/'Hq by sTA'rEsPATEu'r OFFICE. i

RAYMOND iA. HEISING,`OF EAST ORANGE, NEWJERSEY, ASSIGNOB, BY MEBNEASSIGN- MENTS, T0 WESTERN ELECTRIC COMPANY, INCORPORATED, A CORPORATIONOF NEW YORK.

TELEGRAPH SYSTEM.

Specification of Letterllatent. Pate-nteld May 11,1920;

application nica my 12, 1915. serial no. 27,527.

East Orange, in the county of Essex'and State of New Jersey, haveinvented certain new and useful Improvements in Telegraph Systems,`ofwhich the following is a full, clear, concise, and exact description.

This invention relates to telegraph systems and its principal object isto provide an improved method and apparatus for the transmission ofintelligence.

In accordance with its general characteristics the inventioncontemplates a transmitting device selectably and simultaneouslyimparting to a transmission line combinations of electric currents ofdifferent and predetermined frequencies and a receiving devicecontrolled b the currents so iinparted. More speci cally, the receivingdevice comprises a number of electro-frequency selecting systems orinductance and capacity networks, commonly called filters, responsiveonly to currents of frequencies within predetermined limits, convertingsystems for providing unidirectional currents in place of thealternating currents separated out by the respective lters and anelectromagnetic selecting mechanism controlled by currents systems.

The above and other objects of this invention will be fully set forth inthe following description and claim, and'will be more readily understoodby reference to the accompanying drawing wherein Figure 1 shows tliecircuit connections of the preferred embodiment diagrammatically, andFig. 2 shows one method of duplexing.

The multi-frequency transmitter for selectably impressing .upon atransmission line 100, various combinations of electric currents,comprises a plurality of controller switches 101, 102, 103, 104 and 105,which are composed of a movable and two fixed contacts. Normally all ofthe movable contacts are in engagement with the lower fixed contacts.Each of these switches is adapted, when its movable contact is broughtinto engagement with its upper fixed contact, to connect one of aplurality of current generators 111, 112, 113, 114: and 115 vto thetransmission line. The generators'may be continuously driven ataconstant speed, and are so constructed.- and arranged that each from theconverting may impress upon the line currents of differentl frequencieswithin predetermined limits, and preferably of sine wave form, upon theoperation of its corresponding switch 101 to 105 inclusive. Theoperation of various combinations of the switches will cause thesimultaneous transmission of various combinations of superimposedcurrents of various frequencies which may be utilized to selectivelycontrol the operation of a receiver at a distant station.

The controller switches 101 to 105I inclusive may be selectivelyactuated by any of the usual means, such, for example, as the well-knownkeyboard machines wherein character controlling keys are arranged in theform of an ordinary' typewriter keyboard, or automatic devices whoseoperations are controlled by a perforated paper tape or the like.

At the receiving station where the various combinationsof superimposedcurrents are to be translated into desired mechanical ef. fects, such asthe production of printed characters, there are located a number offrequency selecting systems or electro-filtering devices 121, 122, 123,124 and 125, there being one such filter for a given range offrequencies. Each of these filters is associated with the transmissionline through a suitable transformer 126 and comprises asuitableinductance 128 and a capacity 129. The inductance and capacityare so proportioned, in accordance with the well-known laws ofalternating'current phenomena, as to respond readily to currents ofparticular frequencies, nance frequencies, being, however, substantiallyunresponsive to currents of all other frequencies outside of desired orfixed limits. In the embodiment of the invention shown, it will beassumed that filter 121 responds only to the impulses of generatorcommonly known as the reso-l wherein the audion comprises a cathode 136,

and anode 137 and an input electrode 138. Each of the vfilters 121 to125 inclusive is therefore, associated with and may control the actin ofan intermediate relay '141, 142, 143, 144 iind 145, respectively, whosearmatures are associated'with front contacts conv whereupon aunidirectional current is produced. Each of relays 141 to 145 inclusiveis operated by this unidirectional current supplied when its audionbecomes active and causes the energization of a correspondlng selectorrelay 1, 2, 3, 4 and 5, of a selecting mechanism, whlch are providedwith armatures and circuit connections such that, by causing theirenergizatioii in various combinations, any 011ev of lailurality of typemagnets may be energize this arrangement, relay 1 is provided with twoarmatures 11 and 12; relay 2 with three armatures 21, 22 and 23; relay 3has five armatures 31 to 35 inclusive; while relay 4 A hasl eightarmatures 41 to 48 inclusive; and

rela 5 has eleven armatures 51 vto 61 inelusive. By the addition ofother armatures and contacts the possible number` of selections may beincreased.. The ty e 'magnets are designated by the' letters 'ofp thealphabet whose production they control, and may be associated with andlcause the depression of thecharacter keys of an ordinary typewriter, ormay be arranged about the shaft of a rotatable type wheel to arrest itin the desired position in a manner similar to that disclosed in Patent1,107,336, patented August 18, 1914.

vA sucient understanding of the operation of the system will be obtainedfrom a description of the selection of a few particular characters. Inorder to selectv character A,

switch 101 only of the transmitter is operated, which causes current ofthe frequenc determined by generator 1 11 to traverse t e transmissionline. 'As hereinbeforev 1 mentioned, current of this frequency isincapable of influencing any of the filters of the receiver, exceptiilter'121, which, through the agency of audion 135, causes theoperative energization of intermediate relay 141. This relay pulls upits armature and. completes a circuit from grounded source 146 throughselector relay 1, which pulls up its armatures -11 and 1'2. Armature 11completes a circuit/from the negativepole of a Y source of energy 150through conductor 151,

la S1152, 153, 154 an winding of type magnet A, back contacts andarmatures of a 155 to the other pole o source 150. Armature 12 does notcom- In accordance with` contacts and armatures of cut-o plurality ofcut-oil rel plete any circuit since al1 of the circuits conl responsiveaction in none of the filters at the receiving station, except 121 and124,

through Whose associated audions 135 inter.

mediate rela s 141 and 144 are operatively energized. `he attraction ofthe 'armatures of relays 141 and 144 completes circuits from groundedsource 146 through the corresponding selector relays 1 andv4 which pullup their armatures 11'-12 and 41 to 48.

Armatures 12 and 44 complete acircuit from the negative pole of source150 through conductor 160, winding of type magnet H, winding of cut-offrela 152, back contacts and armaturesof cut-o relays 153, 154 and 155 tothe opposite terminal of source 150. Armature' 11 completes thepreviously traced 'circuit through ty e magnet A to the back contact ofcut-o5 relay 152, and

armature 41 completes a circuit from source 150 through con uctor 161and the winding of type magnet D also to the back contact of this relay.Cutoff relay 152, however, is receiving current from the previouslytraced -circuit through type magnet H, and since it is more rapid in itsoperation than any of the type magnets, the circuits throu htypemagnets-A and D are opened at t ey armature of this relaybefore they aresufciently energizedv to cause them to perform their functions. Rela Htherefore'alone is energized, since a stud7 of the drawing will showthat none of the other armatures of relay 4 complete energizingcircuits, and character H will be reproduced by the printing mechanism.

The operation of switch 105 alone causes thetransmission of a current ofa frequency to cause the operation of selector relay .5,

which ulls up its armatures 51 to 61 inclusive. he only armature whichcompletes a circuit is armature 51, which establishes a circuitfromsource 150 through vconductor 162 and type magnet E, through theback relays 152, 153, 154 and 155 to the other pole of source v150,which results in the energization of type magnet E and the production ofthis character.

The operation of any three o f the switches 101 to 105 inclusive willresult in the energi zation vof a combination of ,three of the selectorrelays 1 to 5 inclusive with the resultant attraction of theirarmatures. Because,-however, of the fact that 'some of the circuitspartly prepared by these attracted armatures are open at the armaturesof some of the other selector relays, or are opened before `the typemagnets therein can be energized because of the more rapid operation ofthe cut-off relays 152 to 155 inclusive, only one type magnet will beenergized suiliciently to cause it to effect the printing of itscorresponding character. For convenience in determining the combinationsof impulses required to select any particular type magnet, these magnetshave been arranged in groups, according to the number of impulses reuired to select any type magnet therein. hus the first group is made upof type magnets A to E inclusive, which are selected by one frequencycurrents; the second group comprising magnets F to O inclusive areselected by two frequency currents; type magnets P to U inclusiverequire three frequencies for their selection, while type magnets V, Wand X require four frequencies and type magnet Y requires tive.

It will thus be apparent that by selectively closing switches 101 to 105inclusive in various combinations, resulting in the energization of thecorresponding selector relays 1 to 5 inclusive, any of the type magnetsmay be energized to cause the production of the corresponding type.

This system may be duplexed in the ordinary manner by connecting theapparatus at each end in accordance with Fig. 2. The transmitter isconnected by conductor 158 to the midpoint of an inductive resistance157, one terminal of which is connected to an artificial line AL, theother terminal being connected to line 100. The transformers 126 will bejoined between the terminals of resistance 157 as indicated.

With this system, two messages may be simultaneously transmitted andreceived at opposite ends of the line without duplexing by associatingwith the transmission line at the stationI where the switches 101 to 105are located a set of frequency selecting systems similar to filters 121to 125 inclusive, whose induction and capacity are so -proportioned thatthey are unresponsive to any of the currents controlled byy generators111 to 115 inclusive. These filters may, through the agency of suitableconverting systems and electro-responsive devices, control the actuationof selecting mechanism such as that already described. At the receivingstation where filters 121 to 125 inclusive are located, the transmissionline would be associated with a suitable transmitter provided apparatusfor transmitting and responsivev to different sets of frequencies ateither or each end of the line whereby two or more sets of signals maybe simultaneouslyworked in the same direction.

The invention claimed is:

A system of communication comprising in combination with a lineconductor, a plurality of constantly operating alternating currentgenerators, each generator adapted to produce a frequency or range offrequencies different from that produced by any of the other generators,means for connecting said generators to said line in characteristiccombinations, depending upon the signal to be transmitted, a receivingsystem connected to said conductor comprising a plurality of selectivenetworks, each network having ca pacity and inductance so adjusted as topermit the passage of the current frequencies transmitted by acorresponding one of said generators, but to offer a substantiallimiting impedance to currents, of other frequencies, a vacuum tuberectifier individual to each of said networks having its input circuitconnected to said network, an electromagnetic operation-controllingdevice in the output circuit of each of said amplifiers, and

a printer selecting mechanism under the joint control of saidoperation-controlling devices.

In witness whereof, I hereunto subscribe my name this 11th da of MayA.D. 1915.

RAYM ND A. EISING.

